Features of hydrolysis of specific and nonspecific globular proteins and oligopeptides by antibodies against viral integrase from blood of HIV-infected patients.

It was shown previously that, as differentiated from canonical proteases, abzymes against myelin basic protein (MBP) from blood of patients with multiple sclerosis and systemic lupus erythematosus effectively cleaved only MBP, while antibodies (ABs) against integrase (IN) from blood of HIV-infected patients specifically hydrolyzed only IN. In this work, all sites of effective hydrolysis by anti-IN antibodies (IgG and IgM) of 25-mer oligopeptide (OP25) corresponding to MBP were identified using reversed-phase and thin-layer chromatographies and MALDI mass spectrometry. It was found that amino acid sequences of OP25 and other oligopeptides hydrolyzed by anti-MBP abzymes were partially homologous to some fragments of the full sequence of IN. Sequences of IN oligopeptides cleavable by anti-IN abzymes were homologous to some fragments of MBP, but anti-MBP abzymes could not effectively hydrolyze OPs corresponding to IN. The common features of the cleavage sites of OP25 and other oligopeptides hydrolyzed by anti-MBP and anti-IN abzymes were revealed. The literature data on hydrolysis of specific and nonspecific proteins and oligopeptides by abzymes against different protein antigens were analyzed. Overall, the literature data suggest that short OPs, including OP25, mainly interact with light chains of polyclonal ABs, which had lower affinity and specificity to the substrate than intact ABs. However, it seems that anti-IN ABs are the only one example of abzymes capable of hydrolyzing various oligopeptides with high efficiency (within some hours but not days). Possible reasons for the efficient hydrolysis of foreign oligopeptides by anti-IN abzymes from HIV-infected patients are discussed.

Diversity of integrase-hydrolyzing IgGs and IgMs from sera of HIV-infected patients.

It was previously shown that small fractions of IgGs and IgMs from the sera of AIDS patients specifically hydrolyze only HIV integrase (IN) but not many other tested proteins. Here we present evidence showing that these IgGs and IgMs are extreme catalytically heterogeneous. Affinity chromatography on IN-Sepharose using elution of IgGs (or IgMs) with different concentration of NaCl and acidic buffer separated catalytic antibodies (ABs) into many AB subfractions demonstrating different values of K(m) for IN and k(cat). Nonfractionated IgGs and IgMs possess serine-, thiol-, acidic-like, and metal-dependent proteolytic activity. Metal-dependent activity of abzymes increases in the presence of ions of different metals. In contrast to canonical proteases having one pH optimum, initial nonfractionated IgGs and IgMs demonstrate several optima at pH from 3 to 10. The data obtained show that IN-hydrolyzing polyclonal IgG and IgM of HIV-infected patients are cocktails of anti-IN ABs with different structure of the active centers possessing various affinity to IN, pH optima, and relative rates of the specific substrate hydrolysis.

[Work with public in foci of infection during outbreaks of pneumonia caused by Legionella in town Verkhnyaya Pyshma in July-August 2007].

One of the key elements in epidemiologic control for infectious diseases is timely and active identification of contacts, which results in in-time hospitalization of patients that are needed it and allows to conduct educational work with the public. Measures for outpatient medical and preventive help in Legionella infection which were developed on the experience of termination of outbreak of pneumonia caused by Legionella in town Verkhnyaya Pyshma in July-August, 2007 are presented.

[Organization of medical care of patients with pneumonia caused by Legionella during outbreak in Sverdlovsk region].

Data on organization of medical care during outbreak of Legionnaires' disease in July-August, 2007 in town Verkhnyaya Pyshma in Sverdlovsk region are presented. Special feature of this outbreak was spreading of infection in boundaries of the town with total population of 70,600 people. Results of organizational work of health authorities in order to provide timely and adequate medical care for patients with Legionnaires' disease on both outpatient and inpatient levels of care, conduction of preventive measures in foci of infection, coordination of interaction between different medical organizations and services are summarized in the article.

[Interaction of HIV-1 reverse transcriptase with new minor groove ligands and their conjugates with oligonucleotides].

The influence of new non-natural regular minor groove binders (MGB), containing 2-4 imidazole, pyrrole or thiazole residues, and their conjugates with oligonucleotides, on the polymerization reaction catalyzed by HIV-1 reverse transcriptase was analyzed. Various model template-primer complexes: poly(A)-oligo(U), poly(A)-oligo(dT), poly(dA)-oligo(U), poly(dA)-oligo(dT) and activated DNA were used. The concentration of oligopeptides, giving 50% inhibition (I50) of the RT-dependent polymerization reaction, was shown to depend strongly on the structure of template-primer complexes, number and type of the heterocycle rings in the MGBs analyzed. The range of I50 for the most of the compounds studied is 7.7 x 10(-3)-1.0 x 10(-5) M. The affinity of MGB is minimal for poly(A)-oligo(U). However, some of imidazole and pyrrole-containing MGBs demonstrated unusually high affinity (I50 = 3 x 10(-9)-4 x 10(-8) M) to the above template-primer in complex with RT. The affinity of conjugates of thiazolecarboxamides with oligonucleotides complementary or partially complementary to the template, is 1-4 orders higher compared to free thiazolecarboxamides. The possible reasons of the dependence of I50 values upon the structure of the template-primer complexes, the structure of MGB, and their conjugates with oligonucleotides are discussed.